Title: Transistor ni Venus
Mangaka: Takemoto Izumi
ISBN: 4889917624

Transistor ni Venus is about a female spy who hooks up with a lot of women throughout the course of the manga. It's seven volumes long. For more info, see Okazu's reviews.
This manga is now being scanlated by Lililicious.

Volume 1:

Front cover:

Back cover:

Enus, the main character, meets Mariaana, a telepath who will be her partner for her next mission.

Enus asks Mariaana if she can kiss her. Mariaana says no.

Enus and Mariaana on their mission.

Enus tells Mariaana she has beautiful lips, and asks her if she's often told by people that they want to just eat her right up. Mariaana says no. Enus asks again if she can kiss her and Mariaana, of course, says no.

Enus has finally managed to get Mariaana into her bed... sort of. Mariaana is just giving her a massage. As always, Enus asks for a kiss and is denied.

Enus is working undercover as a maid. She catches another maid who falls off a ladder; the maid apologizes, but Enus says there's no need to apologize, the maid just has to let her kiss her a bit...

Enus is apparently using her powers of seduction to get information.

Enus continues trying to get information out of the other maids; she's kissed all but 2 now (one, after she's kissed the dark-haired girl). And who's the remaining one? Miss Kostas, of course, the woman with the bun and glasses who's always being disapproving of her kissing the other maids. She also seems to be in charge of all the other maids, and so the black-haired maid suggests to Enus that Miss Kostas might know the stuff Enus is asking about. Just then, Miss Kostas comes across them in the bath, and demands to know what Enus is up to. Enus tells Miss Kostas that she's a spy, but says she won't tell her what she's up to unless Miss Kostas lets her kiss her. Miss Kostas gives in, telling Enus to only kiss her a little. Enus apparently goes a little overboard, however. Enus tells Miss Kostas what she's doing, then takes her hair down and kisses her again. Miss Kostas tells Enus to stop; Enus asks her about the info she wants; Miss Kostas says she doesn't know, and so Enus keeps kissing her.

Enus and Miss Kostas.

Enus and Mariaana have ended up chained together at the neck by the enemy. Mariaana turns away from Enus, and Enus tells her she wouldn't try to kiss her in this sort of situation.

Enus and Mariaana managed to escape from the enemy. Enus, having gone in to rescue Mariaana when she was in trouble, tries to put the moves on her now, but is thwarted by Mariaana's injuries.